Drivetrain

Audi offers the perfect transmission for every engine version in the A4 family – ranging from a six-speed manual transmission through a continuously variable multitronic to a sporty seven-speed S tronic. 23 engine/transmission combinations are available for the Sedan and the Avant. All transmissions are characterized by high efficiency, precise operation and a wide gear spread. The lower gears feature short, sporty ratios, while the upper gears are long to reduce revs and fuel consumption.

With all transmissions the differential is located in front of the clutch, shifting the front axle far forward. The positive results are a long wheelbase of 2,808 millimeters (9.21 ft) [A4 allroad quattro: 2,805 millimeters (9.2 ft)] and a balanced axle load distribution.

The total weight of the six-speed manual transmission in the updated Audi A4 is low, and the selector fork bearings decouple the shift lever from vibrations. An on-board computer with efficiency program, standard across the entire model family, integrates a gear-change indicator for manual transmissions.

The manual transmissions paired with the four-cylinder engines are integrated into the innovative thermal management system. A heating loop in the heat exchanger ensures that the transmission fluid is quickly brought up to temperature following a cold start. When the engine’s cooling water is hot enough, a portion of it flows to the transmission.

The multitronic is always paired with front-wheel drive in the A4 model series. This continuously variable transmission allows the engine to almost always operate at its optimal efficiency ratio. It offers dynamic drivers a sport program with shorter gear ratios and a manual mode with eight fixed gear ratios. It can also be shifted via the optional paddles on the steering wheel.

Lightning-fast: the seven-speed S tronic
The sportiest transmission in the A4 model series is the seven-speed S tronic, which is always paired with quattro permanent all-wheel drive. At market launch, it will come standard in the 2.0 TFSI quattro, the 3.0 TFSI quattro and the 3.0 TDI quattro with 180 kW (245 hp).

The seven-speed S tronic consists of two sub-transmissions, which are alternately actuated by two clutches. The direct shifts are executed by this dual-clutch transmission; they take just a few hundredths of a second and are so smooth as to be almost imperceptible. The electronic control system offers a fully automatic mode, with two types of operation: D (Drive) and S (Sport). Drivers can shift as they please, including via optional shift paddles on the steering wheel.

Better traction: quattro permanent all-wheel drive
The quattro permanent all-wheel drive system will be available as an option for some models at market launch. It is obligatory in the A4 allroad quattro. The quattro technology operates by purely mechanical means and therefore entirely instantaneously. It represents the ultimate in driving dynamics, traction, driving safety and straight-line stability.

The central component in the quattro drivetrain is the self-locking center differential. Under typical driving conditions, the planetary gear distributes a majority of the engine’s power to the rear for sportiness – 40 percent to the front axle and 60 percent to the rear axle. If one wheel slips, most of the power goes to the other axle. Up to 70 percent can flow to the front wheels and up to 85 percent to the rear wheels.

Audi combines the self-locking center differential with torque vectoring in the updated A4. This intelligent software solution will detect and respond if an inside front wheel is at risk of losing grip while the vehicle corners at a high speed. It brakes the wheel very slightly before this can happen, making handling even more fluid and traction even stronger.

In the 3.0 TDI quattro, 3.0 TFSI quattro and the S models, the quattro drive system can be supplemented with the sport differential, which actively distributes the power to the rear wheels during dynamic driving. This is accomplished by means of superposition gears operated via multi-plate clutches. They rotate roughly ten percent faster than the drive shaft. When the clutch engages, it applies the higher revs to the wheel on the outside of the curve. The additional torque required in order to rotate faster is drawn away from the inside wheel via the differential.

In faster cornering, the sport differential literally pushes the A4 into the radius. The system’s electronic controller is integrated into Audi drive select and can be switched between multiple characteristics. When the sport differential is on board, the torque vectoring function acts only on the front wheels.

The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.